class_docstr: A memoizing mapping that retains `capacity` deleted items
  
  The memo tracks retained items by their access order; once `capacity` items
  are retained, the least recently used item is discarded.
code: def __setitem__(self, key, value):
      self._memory.pop(key, None)
      self._active[key] = value
  
imports: import inspect
  import warnings
  import types
  import collections
  import itertools
  from functools import lru_cache, wraps
  from typing import Callable, List, Union, Iterable, TypeVar, cast
label_desc: Use image node_id 3 for calling the LRUMemo obj's underlying member method code with example usage: obj.__setitem__(key, value) without return types